The present invention relates to forms for use in manufacturing curb inlet drains for streets and the like. More particularly, the present invention relates to a disposable form for use in casting concrete curb inlet drains in situ.
One known prior art curb inlet drain form is of one piece and is fabricated out of fiberglass. These forms are positioned at the desired location of a curb inlet drain, concrete is poured around them to form the drain, and the forms are left in place. The form is not needed for structural strength, but simply cannot be readily removed. Such forms are presently made by relatively few manufacturers and must be shipped to a contractor for use at a construction site. This requires lead time and subjects the user to limitations on the ability of the manufacturers to meet demand. Moreover, at this time, such forms typically cost several hundred dollars, and such costs add to the price of a construction project.
In some localities, curb inlet drains are cast from on-site fabricated forms. Such forms are typically very costly because of the labor and time needed to construct them. These forms are usually made of exterior plywood which is oiled to permit removal of the form after the concrete has set. Also, such forms are typically destroyed in the process of removing them.
Another known approach is to utilize pre-cast concrete curb inlet drains. To make a pre-cast drain, concrete is poured into a mold which shapes the outer exterior surfaces of the drain. Pre-cast drains typically are extremely heavy, for example, about 500 pounds. For this reason, they cannot be readily handled without special equipment such as a boom truck. Also, the cost of shipping such pre-cast curb inlet drains to a construction site is high. In addition, these pre-cast drains are sometimes difficult to install, for example, to place them level, because of their weight. In addition, because the pre-cast curb inlet drains are typically manufactured away from a construction site, it is difficult for the pre-cast drain to match adjacent concrete which is poured at the site. For example, some differences in texture and coloration may be present which detract from the appearance of the completed construction project. Also, the face of the curb in different localities varies from sloped to vertical. It is sometimes difficult to order pre-cast concrete drain inlets with a curb face which meets the requirements of a particular construction project.
Still another prior art apparatus for forming concrete curb openings is shown in U.S. Pat. No. 2,809,414 of Mitchell. Mitchell discloses a form used in pouring concrete curb inlet openings in situ. Specifically, Mitchell is understood to describe a multi-piece form with pieces which are bolted together to complete the form. This form is removed for reuse by loosening the bolts, where necessary, to disassemble the form and permit its removal after the curb inlet drain has been poured and set sufficiently. In Mitchell, a plate 50 is removed through the mouth of the curb inlet while other pieces are apparently lifted upwardly through a manhole opening formed by the form. A peripheral form piece is also provided for forming a recess or a manhole cover. It appears that the Mitchell form is time-consuming to install and remove.
Other apparatus for forming concrete curb openings are shown in U.S. Pat. Nos. 3,436,051, 4,085,918, and 4,119,291.
Each of these previous drain forms is somewhat expensive to use. A need therefore exists for an improved apparatus for forming curb inlet drains in situ which is directed towards overcoming this and other disadvantages of prior art devices.